The Fairfax County Board of Supervisors voted unanimously Tuesday to approve a massive expansion of Capital One’s corporate headquarters in Tysons Corner — one of the first major projects to win rezoning under a two-year-old master plan that aims to transform Tysons from a sprawling office park to Fairfax’s own urban downtown.

The decision, which was widely expected, came a year and a half after the financial-services giant submitted its application. Capital One owns 26 acres in Tysons near the McLean station on Metro’s Silver Line, which is scheduled to open in late 2013.

Although it will be years before most of it is built, the plan includes 3.1 million square feet of office space, four high-rise residential buildings with as many as 1,200 units, a hotel, 100,000 square feet of restaurants and retail, as well as parks, playgrounds, plazas, bicycle routes, parking structures and new streets. All of it will surround Capital One’s existing corporate headquarters, eventually spanning several blocks.

As part of a package of proffers and public improvements that includes $63 million in transportation contributions, the company will also build a 30,000-square-foot community center with an indoor basketball court and community rooms.

The only building expected to be under construction within the next year would be 20 stories of mostly office space.

(Gene Thorp/The Washington Post)

The project is one of the biggest the county has approved in Tysons Corner since adopting a plan in 2010 that aims to remake the area into a walkable, vibrant downtown over the next several decades. An estimated 100,000 people work in Tysons, and about 18,000 live there. The master plan envisions a city that will be home to 100,000 residents and 200,000 workers by 2050, all anchored by the Metro.

Four Silver Line stations are being built in Tysons. The county wants three quarters of future growth to be within a half-mile of the stops.

The county’s planning commission approved the Capital One project last week. The only feedback Tuesday from members of the public and the board came in the form of thank-yous and congratulations.

“This is a significant rezoning that is very much in concert with the vision for Tysons,” said Sharon Bulova (D), the board chairman.

Supervisor Pat S. Herrity (R-Springfield) thanked Capital One for continuing to invest in Fairfax and bringing jobs. The company now employs about 1,800 people in the county and 14,000 in Virginia.

More than a dozen other proposals from various Tysons applicants are still working their way through Fairfax’s review process. The county will soon decide how best to fund the billions of dollars of road and infrastructure upgrades that will be required over the next 40 years.